Sexually explicit media is a prominent part of the gay community and has been hypothesized to directly impact the way men learn about sex. Since the advent of the Internet, men who have sex with men (MSM) have engaged in online sex-seeking behaviors, including consumption of MSM-specific sexually explicit online media (SEOM). There has been remarkable growth in the MSM-specific SEOM industry and a rise in unprotected sex in MSM-specific SEOM. This has raised concerns about the potential for encouragement of risky sex among SEOM consumers. Despite these concerns, to the applicant's knowledge there has been no research examining SEOM consumption in MSM or associations between SEOM consumption and HIV risk- taking in MSM. Research in this area has tremendous potential to harness MSM-specific SEOM as a means of quickly and inexpensively disseminating HIV prevention messages to a wide audience of at-risk MSM. As research in this area is in its infancy, formative research on measurement and associations between SEOM and sexual behaviors is needed in the development of a much larger program of research. To address these formative needs, the applicant proposes a mixed-methods study. Specifically, a MSM-specific SEOM measure will be drafted using extensive online research of MSM-specific SEOM websites and in- depth qualitative interviews with online partner-seeking MSM (N=15), tested via cognitive interviews with the same group of MSM (N=15) as well as an additional sample of online partner-seeking MSM (N=15), and finalized via online pre-testing with a sample of online partner-seeking MSM (N=100). Using this SEOM measure, a cross-sectional online survey of online partner-seeking MSM (N=1,100) will examine associations between SEOM exposure and sexual behaviors in MSM. The applicant, a top clinical psychology student at the #1 program in the US with an MPH in epidemiology and extensive experience in MSM-specific HIV prevention research, has assembled a research team that is well suited to support her in achieving her fellowship goals. This predoctoral fellowship will be her first step in the development of systematic program of research ultimately leading to an innovative online HIV prevention intervention and will situate her well for a postdoctoral research position. PUBLIC HEALTH RELEVANCE: As MSM continue to have the highest rates of IV infection in the US, there continues to be an urgent need for innovative HIV prevention methods directed toward them. A large industry of sexually explicit online media targets MSM and could provide a quick, inexpensive way to disseminate safer-sex messages to a wide audience of at-risk MSM.